Store cupboard science for the festive season – making curds and whey

Curds and Whey

Fancy making a bit of cheese to enjoy over Christmas?

You’ll need: 200ml milk, lemon juice, a pan, sieve and clean tea towel. Plus an adult to help.

Slowly heat them milk on a medium heat until it boils – stirring all the time. Once it boils turn off the heat and leave to cool for 2 mins. Add 3 teaspoons of lemon juice and stir.  The milk should start to curdle and turn into curds and whey.  Strain the curds using a sieve lined with kitchen tea towel, leave to drain and try the curds which are a form of cheese that you have made. Try it on a cracker with a bit of honey!

The why about the whey!

Milk is a colloid – it is made up of different particles – curds (casein) and whey (liquid) which are blended smoothly together and wont separate on their own.  When we add the acidity of lemon juice to the casein which is a protein it curdles the milk and the casein particles turn into chunky curds because they can’t mix with the lemon juice